Lipoteichoic acid (hereinafter referred to as "LTA"), lipopolysaccharide (hereinafter referred to as "LPS") and the like have heretofore been known as amphipathic substances which are extracted from, for example, the whole cell of Gram-positive bacteria and Gram-negative bacteria or a fraction including the cell wall and cytoplasmic membrane of such bacteria (such fraction being referred to as a "cell envelope fraction", hereinafter).
In 1975, Old et al, reported a tumor necrosis factor (TNF) which is a glycoprotein that specifically attacks only tumor cells without damaging normal cells (Proc. Natl. Acad. Sci. U.S.A., 72, 3666). According to this report, it is possible to induce TNF in serum by administering live BCG or the like into the vein of a mouse and administering LPS one to two weeks later. However, the lethal toxicity of LPS is extremely high; for example, if 0.8 .mu.g/head or more of LPS is administered to mice sensitized with BCG, the greater part of the mice will die within six hours. Accordingly, employment of LPS itself as a medicine such as a cancer controlling agent involves clinical problems.